package org.dong.common.utils;

import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Service;

@Service
public class Context implements ApplicationContextAware {
	
	private static ApplicationContext applicationContext;

	/**
	 * 实现ApplicationContextAware接口的context注入函数, 将其存入静态变量.
	 */
	public void setApplicationContext(ApplicationContext applicationContext) {
		Context.applicationContext = applicationContext; 
	}

	/**
	 * 从静态变量ApplicationContext中取得Bean
	 */
	public static <T> T getBean(Class<T> clazz) {
		checkApplicationContext();
		return (T) applicationContext.getBean(clazz);
	}

	/**
	 * 清除applicationContext静态变量.
	 */
	public static void cleanApplicationContext() {
		applicationContext = null;
	}

	private static void checkApplicationContext() {
		if (applicationContext == null) {
			throw new IllegalStateException(
					"applicaitonContext为null！");
		}
	}
}